Air zone reports are prepared each year by the B.C. Ministry of Environment and Climate Change Strategy to summarize the levels of air pollution in reporting areas called “air zones”. The reports are part of our commitment under the national Air Quality Management System (AQMS) to better protect human health and the environment.
This annual report, titled “Air Zone Report (2019-2021)”, summarizes B.C.’s air quality status, achievement of the Canadian Ambient Air Quality Standards (CAAQS), and assignment of management levels for the four major pollutants: fine particulate matter (PM2.5), ozone, nitrogen dioxide (NO2), and sulphur dioxide (SO2). Management levels are assessed based on three years (2019-2021) of monitoring data. Under the principles of the AQMS, management levels define the recommended level of actions for communities in order to keep clean areas clean and continuously improve air quality.
Air pollution is recognized as one of the greatest environmental threat to human health (WHO 2022). Based on Health Canada estimates, approximately 15,300 Canadians–1,900 in British Columbia–prematurely die every year due to exposure to air pollution (Health Canada 2021). In order to protect human health, ministers of the environment agreed to implement the Air Quality Management System.
The national Air Quality Management System (AQMS) provides a collaborative and comprehensive approach of managing ambient (outdoor) air quality. AQMS is implemented across Canada to reduce emissions and levels of major air pollutants. B.C. is divided into seven air zones to help manage air quality across the province.
The pollutants listed below are considered to have the strongest evidence of major health concern. These pollutants have been the focus of health impact studies, and among the pollutants with established air quality objectives. Under the Air Quality Management System, the Canadian Ambient Air Quality Standards (CAAQS) were developed to serve as driver for the continuous improvement of air quality. The Canadian Environmental Protection Act have also established CAAQS as national air quality objectives for these four pollutants.
This report uses metrics to summarize the levels of each pollutant and compare it to the Canadian Ambient Air Quality Standards. A metric consists of:
a numerical value that represents the concentration or level of pollutant;
unit of measurement defines the kind of quantity that the numerical value represents; and
statistical form that specifies how the numerical value was calculated using raw measurements.
Click on the list below for more information about each pollutant
Fine particulate matter (PM2.5) are solid particles or liquid droplets that are suspended in air with sizes smaller than or equal to 2.5 micrometres (µm) in diameter. PM2.5 are typically found in smoke, soot, dust, dirt, dispersed aerosol, and biological sources like mould, bacteria, pollen, and animal dander. When inhaled, these particles travel deep into the lungs and the bloodstream and can cause adverse health effects, such as cardiovascular and respiratory diseases. PM2.5 is considered a non-threshold pollutant, that is there are associated health effects at any level of exposure.
In this report, PM2.5 is presented using any of the two metrics. - an annual metric to estimate long term exposure - a 24-hour metric to estimate short term or acute exposure.
Ground-level ozone (O3), is a colourless, odourless and highly irritating gas that forms close to the Earth’s surface. O3 is a major component of smog. In contrast to “primary” pollutants which are emitted directly into the atmosphere from a source, O3 is considered a “secondary” pollutant because it is formed through complex chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. While O3 at ground-level is a significant environmental and health concern, approximately 10 to 40 kilometres above the Earth’s surface, there is a beneficial layer of stratospheric ozone which shields the earth from harmful ultraviolet radiation. Ozone is also a short-lived climate pollutant and also contributes to climate change.
In this report, O3 is presented using the 8-hour metric.
Nitrogen dioxide (NO2) belongs to the oxides of nitrogen group of compounds (NOx) that are formed primarily through the burning of fossil fuels. While transportation sources represent over half of all emissions, energy production and industrial processes also emit significant amounts of NOx, mainly as Nitric Oxide (NO) and Nitrogen Dioxide (NO2). NO2 at higher concentrations has a strong, harsh odour and can typically be seen over large cities as a brownish haze. Once formed, NO2 can combine with water molecules in the air to form compounds like nitric acid and nitrous acid. Ultimately, these compounds fall to earth through precipitation (such as rain, snow and fog) where they contribute to the acidification and eutrophication of ecosystems.
In this report, NO2 is presented using any of the two metrics. - an annual metric to estimate long term exposure, and 1-hour metric to estimate short term or acute exposure.
Sulphur dioxide (SO2) is a colourless gas that smells like burnt matches. It belongs to a group of sulphur-containing gases called sulphur oxides (SOx). SO2 is emitted when fossil fuels or raw materials containing sulphur are burned or used in an industrial process like metal ore smelting or electric power generation. It can also be produced in large quantities during extraction and processing of fossil fuels. SO2 contributes to the formation of PM2.5 and smog, and when combined with water molecules in the air, it can form compounds like sulfuric acid, which eventually falls to earth as acid rain, snow and fog.
In this report, SO2 is presented using any of the two metrics. - an annual metric to estimate long term exposure, and 1-hour metric as estimate of acute (short term) exposure.
Pollutant levels have mostly remained lower than the Canadian Ambient Air Quality Standards and has improved throughout the years. PM2.5 is an exception due to the increasing intensity and frequency of wildfire smoke.
Fine Particulate Matter (PM2.5) annual metric, ↑22% (since 2000)
Fine Particulate Matter (PM2.5) 24-hour metric, ↑60% (since 2000)
Ozone (O3) 8-hour metric,↓16% (since 1990)
Nitrogen Dioxide (NO2) annual metric,↓65% (since 1990)
Nitrogen Dioxide (NO2) 1-hour metric,↓58% (since 1990)
Sulphur Dioxide (SO2) annual metric,↓94% (since 1990)
Sulphur Dioxide (SO2) 1-hour metric,↓92% (since 1990)
Emissions of key air pollutants from industrial and mobile sources (excluding dust, and smoke from woodstoves and open burns) have been declining from 1990 levels. In 2020:
Air quality monitoring stations are installed to measure the levels of pollutants on communities. These stations are maintained and operated either by the Ministry of Environemtn and Climate Change Strategy, Metro Vancouver Regional District, Community air quality roundtable, industrial permit holders, and other agencies (BCHydro, Prince Rupert Port Authority, BC Oil and Gas Commission, etc.). Only stations developed to monitoring community exposure-not the fenceline stations-are included for AQMS reporting.
Some of the stations are included in the Air Quality Health Index (AQHI) reporting. These stations contain multiple instruments for the simultaneous monitoring and near real-time reporting of PM2.5, O3, and NO2. AQHI is a tool to communicate the health impact of poor air quality.
The map below shows the location of air quality monitoring stations in B.C.
Each air zone is assigned a colour-based management level for each of the four pollutants (particulate matter, ozone, nitrogen dioxide, and sulfur dioxide). These management levels are based on the levels of pollution measured from communities inside the air zone.The management levels also correspond to air zone management actions that are recommended under the Air Quality Management System. Provinces and territories, in collaboration with communities, use the management levels as framework to develop action plans and policies to address the issue of the pollutant.
Pollutants that traveled across boundaries (trans-boundary) or are formed from exceptional events such as wildfires, are typically omitted from the assessment in order to focus on community-level actions and continuously improve air quality. The AQMS also applies other regulatory and non-regulatory instruments. This includes Base Level Industrial Emission Requirements to reduce emissions from industry and industrial equipment, and an inter-governmental collaboration to reduce vehicle emissions.
| Air Zone | PM₂.₅ | Ozone | NO₂ | SO₂ |
|---|---|---|---|---|
| Central Interior | 4 of 7 sites | Prince George-Plaza 400, Williams Lake | All 4 sites | Prince George-Plaza 400, Quesnel |
| Coastal | Kitimat-Riverlodge, Terrace | Prince Rupert-Fairview, Terrace | Prince Rupert-Fairview, Terrace | All 4 sites |
| Georgia Strait | 7 of 13 sites | 4 of 7 sites | Victoria | All 3 sites |
| Lower Fraser Valley | Vancouver-ClarkDr | 6 of 23 sites | 17 of 23 sites | All 17 sites |
| Northeast | FortSt.John | FortSt.John, Taylor-Townsite | FortSt.John, Taylor-Townsite | FortSt.John, Taylor-Townsite |
| Northwest | Data Not Available | Data Not Available | Data Not Available | Data Not Available |
| Southern Interior | Grand Forks, Vernon | 4 of 5 sites | Kamloops, Vernon | Trail-Butler Park |
Pollution from fine particulate matter remains the major problem in B.C. These pollution mostly comes from smoke from the seasonal wildfire season. However, there are also winter-time events that are
According to the Environmental Management Act of British Columbia, an air contaminant is a substance introduced into the air that can affect the health or safety of a person, affects visibility, can cause damage or injury to propery, lifeform, and the environment. British Columbia monitors the levels of several air pollutants that are associated with effects on health and the environment. These pollutants have various diverse sources including vehicular traffic, residential woodstoves, industrial emissions, and wildfires. There are four air pollutants that are included in an air zone reports. These are the pollutants considered to be major public health concern due to prevalence and potential to affect health.
In British Columbia, air quality has seen improvements, particularly in the levels of fine particulate matter, ozone, nitrogen dioxide, and sulphur dioxide.
Add description for the trends of some pollutants based on the ECCC National Pollutant Release Inventory
